This discovery was made by a team of researchers who study skin-related pain. It was published in Pain Medicine, the official journal of the American Academy of Pain Medicine. The study focused on women who suffer from fibromyalgia pain and sensitivities in their hands.

In the study, researchers used microscope technology to examine the nerve endings in skin tissue samples taken from the palms of the participant’s hands. What they discovered was a huge proliferation of sensory nerve fibers near the blood vessels of the skin. They concluded that altered blood flow may be the source of fibromyalgic pain!

This finding is very exciting because altered blood flow could conceivably be the cause of most symptoms associated with fibromyalgia pain: deep muscular aches, joint pain, insomnia, and cognitive issues. The current theory of centralized pain is just not specific enough to explain major fibromyalgia symptoms.

How Sensory Nerve Fibers Control Blood Flow in the Hands

Sensory nerve fibers are found just under the top two layers of skin. Their job is to sense and transmit heat, pain, and other uncomfortable sensations. When sensory nerve fibers malfunction, a person may experience tingling sensations, pins-and-needles, numbness, burning, and pain.

Sensory nerve fibers are also involved in blood flow and temperature control. There is a close interaction between sensory nerve fibers and sympathetic nerve fibers in order to control blood flow throughout the body.

Blood supplies nutrients to the muscles, nerves, organs, and tissues. It also carries away waste products.

When we engage in any activity, we use our muscles. Muscle activity generates heat. Muscle-generated heat related to activity or exposure to environmental heat can cause the body to become over-heated. To cool itself off and protect vital core organs, the body sends the heat (carried in the blood) to the hands and the feet. Hands and feet appear to be reservoirs of blood in the body directly related to temperature control. Blood also supplies nutrients to the muscles, nerves, organs, and tissues while carrying away waste products.

Sensory nerve endings in the hands and the feet connect to and control tiny muscular valves of the circulatory system, known as arteriole-venule (AV) shunts. Sensory nerves signal the AV shunts to open or close, regulating blood flow to release or conserve body heat.

The Problem with Excess Sensory Fibers and Overstimulated Sympathetic Nerves

The researchers suggest that the presence of excess sensory nerve fibers in the palms of the hands and feet may be interfering with the smooth flow of blood through the body.

Perhaps the excess sensory nerves are overstimulating the sympathetic nerves or vice-versa to cause AV structures to constrict blood flow. Over-constriction would interfere with efficient temperature control, the smooth flow of blood to the deep muscles of the body and the cognitive centers of the brain.

Altered blood flow begins to explain some of the symptoms related to fibromyalgia pain: fatigue, build up of lactic acid in muscles, difficulty sleeping, and deep-seated muscle aches.

The next step in this research is to see if men, who also suffer from fibromyalgia, have excess sensory fibers in the palms of their hands and feet.

The findings of this study echo theories of pain proposed in Traditional Chinese Medicine, known as Liver Depression Qi Stagnation which will be the subject of a future post!